import java.io.*;
import java.lang.Math;
public class Main {
	float a,b,c;
	public float fac(Main x)
	{
		float p,s;
		p=(x.a+x.b+x.c)/2;
		s=(float)Math.sqrt(p*(p-x.a)*(p-x.b)*(p-x.c));
		return s;
		
	}
	public  float fac1(Main x)
	{
		float sum;
			sum=x.a+x.b+x.c;
		return sum;
	}
	public static int fac2(Main x)
	{
		
		if(x.a+x.b>x.c&&x.a+x.c>x.b&&x.c+x.b>x.a)
		 return 1;
		else
			return 0;
		
	}
	public Main(float x1[])
	{
		a=x1[0];
		b=x1[1];
		c=x1[2];
	}
	public static void main(String[] args ) {
		 float b[]=new float[3];
		 int i;
		 String s="";
		System.out.println("请输入三角形三边：");
		for(i=0;i<b.length;i++)
		 {
			 try {
				 BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
				 s=in.readLine();
			 }catch(IOException e) {}
			 b[i]=Integer.parseInt(s);	 
		 }
		Main m=new Main(b);
		if(fac2(m)==0)
		{
			System.out.println("该三边够不成三角形");
			return ;
		}
		System.out.println("三角形的面积为："+m.fac(m));
		System.out.println("三角形的周长为："+m.fac1(m));
	}
}